A team of scientists, including a guy named McGill a University geologist at Christie Rowe, has published a set of studies in the journal of Science that sheds light on what caused the dramatic displacement of the seafloor off the northeastern coast of Japan. The findings they found also suggest that other zones in the northwest Pacific may be at risk of similar huge earthquakes that would occur sometime again. Professor Rowe, of McGill's Department of Earth & Planetary Sciences, was one of the 27 scientists from 10 countries who participated in a 50-day expedition in 2012 on the Japanese drilling vessel, Chikyu. The team drilled three holes in the Japan Trench area to study the rupture zone of the 2011 earthquake deep beneath the surface of the Pacific Ocean.

What I learned in this article is that the joint where the Pacific and North American plates meet forms what is known as a "sub-duction" zone, with the North American plate riding over the edge of the Pacific plate. The latter plate bends and plunges deep into Earth, forming the Japan Trench. Another thing I learned is that scientists also discovered that the clay deposits that fill the narrow fault are made of extremely fine sediment. The discovery of this unusual clay in the Tohoku slip zone suggests that other sub-duction zones in the northwest Pacific where this type of clay is present. To conduct the studies, the scientists used specially designed deep-water drilling equipment that enabled them to drill more than 800 meters beneath the sea floor, in an area where the water is around 6,900 meters deep.At those extraordinary depths, it took six hours from the time the drill pulled core samples from the fault until it reached the ship. All these facts that I learned are amazing and I enjoyed learning them.

This has to do with oceanography in many ways. Tsunamis can be generated by more than just earthquakes. The vertical movement of the ocean surface can also be caused by land-slides (or undersea slumping), cyclones (a so-called ‘meteo-tsunami’). or even by meteorite impacts. Also, this has to do with oceanography because what is important for a tsunami is that the wave generated has a very long wavelength (the distance between two crests or troughs). This long wavelength, of around 200 kilometres, means that the period of the wave (the time it takes for two crests to pass) is also very long, around 15–30 minutes. It is this long wavelength that means the wave travels so fast in deep water because it is effectively a shallow water wave (the wavelength is much larger than the depth of the ocean which is only about four kilometres). The long wavelength is also the reason that such a shallow wave contains so much energy. It is this energy that is rapidly released as the tsunami moves into shallow water and slows down. During the slow down, the energy in the wave becomes compressed and the wave becomes much higher and steepens, leading to the monster waves that cause so much damage.

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